The act of having sex while the woman holds onto the bedposts and sticks her legs straight out (but with distance between them) while the man hold her body straight out during penetration...resulting in the female being in a superman-flight position.

Bob: "Wow, your sister must work-out."
Tom: "Why do you say that?"
Bob: "We were SuperManing last night for thirty minutes before her legs gave out."
Tom: "Fuck you man."

To start off two naked dudes sit doggy style on the bed with their butts towards you. You then turn on soulja boy crank that and wait for it to say "superman." You then stick both fists straight out and proceed to launch your self towards their assholes. Mid air your fists stick straight in and you are completely off the ground.